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Contains fulltext : 203356.pdf (publisher's version ) (Open Access), Despite being a rare congenital limb anomaly, triphalangeal thumb is a subject of research in various scientific fields, providing new insights in clinical research and evolutionary biology. The findings of triphalangeal thumb can be predictive for other congenital anomalies as part of an underlying syndrome. Furthermore, triphalangeal thumb is still being used as a model in molecular genetics to study gene regulation by long-range regulatory elements. We present a review that summarizes a number of scientifically relevant topics that involve the triphalangeal thumb phenotype. Future initiatives involving multidisciplinary teams collaborating in the field of triphalangeal thumb research can lead to a better understanding of the pathogenesis and molecular mechanisms of this condition as well as other congenital upper limb anomalies.

Contains fulltext : 215622.pdf (publisher's version ) (Closed access), CONTEXT: Thyroid hormone is important for normal brain development. The type 2 deiodinase (D2) controls thyroid hormone action in the brain by activating T4 to T3. The enzymatic activity of D2 depends on the incorporation of selenocysteine for which the selenocysteine-insertion sequence (SECIS) element located in the 3' untranslated region is indispensable. We hypothesized that mutations in the SECIS element could affect D2 function, resulting in a neurocognitive phenotype. OBJECTIVE: To identify mutations in the SECIS element of DIO2 in patients with intellectual disability and to test their functional consequences. DESIGN, SETTING, AND PATIENTS: The SECIS element of DIO2 was sequenced in 387 patients with unexplained intellectual disability using a predefined pattern of thyroid function tests. SECIS element read-through in wild-type or mutant D2 was quantified by a luciferase reporter system in transfected cells. Functional consequences were assessed by quantifying D2 activity in cell lysate or intact cell metabolism studies. RESULTS: Sequence analysis revealed 2 heterozygous mutations: c.5703C>T and c.5730A>T, which were also present in the unaffected family members. The functional evaluation showed that both mutations did not affect D2 enzyme activity in cell lysates or intact cells, although the 5730A>T mutation decreased SECIS element read-through by 75%. In the patient harboring the c.5730A>T variant, whole genome sequencing revealed a pathogenic deletion of the STXBP1 gene. CONCLUSIONS: We report on two families with mutations in the SECIS element of D2. Although functional analysis showed that nucleotide 5730 is important for normal SECIS element read-through, the two variants did not segregate with a distinct phenotype.

Item does not contain fulltext, Refractive errors, including myopia, are the most frequent eye disorders worldwide and an increasingly common cause of blindness. This genome-wide association meta-analysis in 160,420 participants and replication in 95,505 participants increased the number of established independent signals from 37 to 161 and showed high genetic correlation between Europeans and Asians (>0.78). Expression experiments and comprehensive in silico analyses identified retinal cell physiology and light processing as prominent mechanisms, and also identified functional contributions to refractive-error development in all cell types of the neurosensory retina, retinal pigment epithelium, vascular endothelium and extracellular matrix. Newly identified genes implicate novel mechanisms such as rod-and-cone bipolar synaptic neurotransmission, anterior-segment morphology and angiogenesis. Thirty-one loci resided in or near regions transcribing small RNAs, thus suggesting a role for post-transcriptional regulation. Our results support the notion that refractive errors are caused by a light-dependent retina-to-sclera signaling cascade and delineate potential pathobiological molecular drivers.

Item does not contain fulltext, PURPOSE: The zone of polarizing activity regulatory sequence (ZRS) is an enhancer that regulates sonic hedgehog during embryonic limb development. Recently, mutations in a noncoding evolutionary conserved sequence 500 bp upstream of the ZRS, termed the pre-ZRS (pZRS), have been associated with polydactyly in dogs and humans. Here, we report the first case of triphalangeal thumb-polysyndactyly syndrome (TPT-PS) to be associated with mutations in this region and show via mouse enhancer assays how this mutation leads to ectopic expression throughout the developing limb bud. METHODS: We used linkage analysis, whole-exome sequencing, Sanger sequencing, fluorescence in situ hybridization, multiplex ligation-dependent probe amplification, single-nucleotide polymorphism array, and a mouse transgenic enhancer assay. RESULTS: Ten members of a TPT-PS family were included in this study. The mutation was linked to chromosome 7q36 (LOD score 3.0). No aberrations in the ZRS could be identified. A point mutation in the pZRS (chr7:156585476G>C; GRCh37/hg19) was detected in all affected family members. Functional characterization using a mouse transgenic enhancer essay showed extended ectopic expression dispersed throughout the entire limb bud (E11.5). CONCLUSION: Our work describes the first mutation in the pZRS to be associated with TPT-PS and provides functional evidence that this mutation leads to ectopic expression of this enhancer within the developing limb.

Item does not contain fulltext, BACKGROUND: Ustekinumab is a fully human anti-p40 monoclonal antibody which neutralizes interleukin (IL)-12 and IL-23, thereby interfering with T-helper (Th)1/Th17 pathways and keratinocyte activation, and is highly effective in the treatment of psoriasis. During ustekinumab treatment, some of our patients noticed reduced koebnerization of noninvolved skin and less new plaque formation. OBJECTIVES: To determine whether ustekinumab improves psoriasis-related gene expression and tape-strip responses in noninvolved skin. METHODS: Before and 4 weeks after ustekinumab treatment, noninvolved skin was tape-stripped. After 5 h, biopsies were taken from untouched and tape-stripped skin. The mRNA expression of psoriasis-related markers such as NGF, GATA3 and IL-22RA1, and several antimicrobial peptides (AMP) was quantified. Leucocyte counts and a broad range of inflammatory serum proteins were analysed to gain insight into the systemic alterations. RESULTS: Four weeks following a single ustekinumab injection, NGF showed a significant decrease, whereas GATA3 and IL-22RA1 expression increased, indicative of reduced responsiveness to epidermal triggering. This was accompanied by an increase of the inflammation-related serum proteins GPNMB, MST1 and TRADD. The baseline and tape-strip-induced mRNA expression of the AMP human beta-defensin-2 (hBD-2), S100A7 and LL-37 remained unaltered. Clinically, after 4 weeks, eight out of 11 patients showed a 50% psoriasis area and severity index (PASI) improvement, which was accompanied by a significant reduction in serum hBD-2 levels. No changes were noted in total leucocytes, C-reactive protein and erythrocyte sedimentation rate. CONCLUSIONS: These findings indicate that ustekinumab reduces psoriasis-related gene expression in noninvolved psoriatic skin, making it more resistant to exogenous triggering, without disturbing its antimicrobial response. In parallel, ustekinumab modulates important circulating inflammation-related proteins.